The present invention relates to a method and a device for testing a brain lesion electrode which is intended for use in treatment of a specified area in the brain, for instance, by controlled coagulation or lessening.
More specifically, the invention relates to a system for quick-testing electrodes that are used in surgical operations in the brain, such as bipolar coagulation and lessening for neurosurgery, and impedance measurement as well as stimulation, at a controlled temperature of the electrode tip.
The brain lesion electrode can be a monopolar electrode, the other electrode or backplate electrode preferably being a metal plate which is arranged in electrically conductive contact with the patient's skin, for instance, on the patient's back. The backplate electrode or reference electrode can also be assembled with the active electrode to form a unit, i.e. a bipolar electrode or a double electrode consisting of two monopolar electrodes.
The above-mentioned electrodes are intended to be used together with a power unit with the possibility of controlling current intensity, frequency, duration of the treatment periods etc. and with monitoring and indicating functions for, inter alia, the temperature of the brain lesion electrode. An example of a suitable power unit is LEKSELL.RTM. NEURO GENERATOR, which is commercially available at Elekta Instrument AB in Sweden. A suitable device for positioning and holding the electrode when in use is disclosed in, for example, U.S. Pat. No. 5,116,344.
Before the brain lesion electrode is put into use, it is most important to make sure that the electrode operates in the intended fashion. Of course a built-in test system is available in the power unit, but it may be difficult to discover certain deficiencies of the electrode, such as. a defective thermocouple in the electrode or an unsatisfactory coating of the electrode.